292 Memoir on Indian Earthquakes. [No. 136. 



tion of the shock at that place. At Baughulpore (lat. 25° 13' N. 

 long. 86° 58' E.) I am informed by Mr. Piddington, that the shock 

 was not felt. 



It therefore appears that, in so far as the facts collected extend, the 

 tract affected by the Earthquake of the 11th November 1842, was 

 bounded on the North by Darjeeling, on the East by Chittagong, on 

 the West by Monghyr, and on the South by the position of the ship 

 Agincourt, thus including about five degrees of longitude and five 

 of latitude. That to the Eastward and Southward, and probably to 

 the Northward also, the shock extended beyond the limit here assign- 

 ed, can scarcely be doubted, from its intensity at the places specified 

 as the bounding points of the tract in these directions, but there is no 

 information available to prove that it did do so, and I am unwilling to 

 venture upon conjecture. 



It will have been observed, that at different places the shock appear- 

 ed to travel in every different direction. Thus : — 



At Calcutta, the direction was from E. N. E. to W. S. W. 



At Pubna, „ from S. W. to N. E. 



At Darjeeling „ from S. to N. 



At Chittagong „ from N. to S. 



Now, it appears to me, that the only way in which these statements 

 can be connected and rendered consistent, is to conceive the undula- 

 tions of which the shock was composed, to have been propagated in a 

 manner analogous to waves formed in water when a stone is thrown 

 into it. Proceeding thus in all directions from a central point, the 

 undulations would seem to observe to come from different directions, 

 dependent on their position, relative to the centre whence the undula- 

 tions had emanated. Of course waves propagated through the crust 

 of the earth could retain but little of that perfect symmetry character- 

 istic of waves in a homogenous fluid like water, since their forms would 

 necessarily be modified by the variable nature of the strata through 

 which they were being transmitted, and hence departures from strict 

 theoretical accuracy of direction are to be anticipated. Assigning 

 therefore a certain degree of circularity to the undulations of the 

 Earthquake of the 11th Nov. and conceiving the centre of ema- 

 nation to have been some little distance to the N. E. of Calcutta, 

 it will be found that the observations on direction become to some 



